“Immature persons without moral imagination like to look upon the instincts of their underdeveloped natures as the full content of humanity, and to reject all moral ideas which they have not produced, I order that they have not produced, in order that they may ‘live themselves our’ without restriction. But it is obvious that what holds good for a fully developed human being does not apply to one who is only half-developed. One who still has to be brought by education to the point where his moral nature breaks through the shell of his lower passions, cannot lay claim to what applies to a man who is mature. …
“The fully mature man gives himself his value. … He acts in accordance with his ethical intuition, and in the attainment of what he wants he feels the true enjoyment of life.” ~Rudolf Steiner
When we talk about maturity here, we are concerned more with spiritual maturity than with the physical, but there is some overlap. Clearly, a person who is mentally immature is not going to seek spiritual development, but a person can be physically and mentally mature without being spiritual at all. Even a person with a half dozen college degrees may be spiritually immature, and not even be aware of it. The really sad thing is that many of our institutions, including great universities and governments, place little value on spiritual maturity. Oh, yes they do lip service to religion, but only insofar as those religions stick with teaching ethical behavior in the world of materialism. They shun any church or spiritual school that teaches actual spiritual development.
So both the materially immature and the materially mature need to work on becoming spiritually mature, and it is arguable which group has the greater difficulty.
The materially immature person may be more easily convinced to join a spiritual school and engage is spiritual awakening and growth techniques taught only to members of such schools, but he may have difficulties in the material world that will pull him away from such studies regularly, and eventually cause him to quit. But don’t confuse immature with uneducated. Some people may lack a formal education, yet be quite mature on the physical and mental level. For such a person who does pursue a spiritual awakening, the rewards can be great and relatively quick since he has little to change. He can more readily accept truth when his brain hasn’t been stuffed with lies and illusions. And awakening those spiritual faculties can actually aid these people in maturing on the mental level as well.
The materially mature person can also get great rewards from developing his spiritual side, but it is usually much harder to convince him to do so. When you are well educated, have a good paying job, have plenty of material things to play with, you are not very likely to be seeing something else. But many people who have such success find it unsatisfying. The usual response is to seek even more of the same: more money, more travel, more homes, more things of every possible kind. And when that fails, even more. Only a few ever realize that they will not be satisfied by this forever seeking more and more material wealth because deep down their soul craves something else. Those few may seek out, or be contacted by, a spiritual school that can meet those needs. These seekers may have great difficulty at first because it is so different from what they have learned in the world of materialism. Those who stick it out are greatly rewarded, though. And these people, because of their knowledge of the world of matter, and their contacts in it, can make good teachers and recruiters for spiritual schools.
So whether we are mentally mature or immature, it is a benefit to all to become spiritually mature and develop those spiritual faculties that lie dormant in most of us.